In the operation of certain types of harvesting machines such as combines, harvested materials are processed by a threshing mechanism wherein most of the kernels of grain are separated from the materials other than grain. Subsequent cleaning of the threshed materials is usually provided for by a cleaning system from which cleaned grain exits. As used herein, the term "grain" is meant to include corn, wheat, rye, oats, barley, flax seed, sorghum, soy beans, sunflower seeds, grass seeds, alfalfa, mixed grain, rice, and any other food grain, feed grain, oil seeds and the like.
A combine used to harvest grain is typically equipped to operate at a variety of ground speeds to accommodate different crop conditions. Crop conditions which vary include crop density, moisture content of the crop, desired quality of grain, and straw per acre. As will be appreciated, all these factors affect the harvesting of the crop.
Prescription farming or tuning of fertilizer or pesticide applications can have a significant influence on crop yields. Heretofore, however, the farmer has not been provided with means suitable to accurately measure grain yields during the harvest and therefore the farmer cannot estimate the possible large spatial variations in crop yields. Moreover, data relating to mass grain flow measurements, if available, could be used by a farmer to reference the order-of-magnitude of crop yields when dealing with traders and shippers.
Thus, there is a need and a desire for a system which monitors mass flow of clean grain in a combine.